Serious adverse events
| Serious adverse event | Number of events | |
| Viral respiratory tract infection | 45 | |
| Gastritis and gastroenteritis | 23 | |
| Bronchiolitis | 20 | |
| Accidental injury or overdose | 9 | |
| Elective surgical treatment/EUA | 10 | |
| Gastro-oesophageal reflux | 6 | |
| Anorexia and feeding problems | 4 | |
| Constipation | 2 | |
| Dysphagia | 1 | |
| Vomiting | 1 | |
| Periorbital cellulitis | 1 | |
| Pertussis | 1 | |
| Colic | 2 | |
| Injection site haemorrhage | 1 | not at site of Men C injection |
| Pneumonia | 1 | |
| Intussusception | 2 | |
| Tonsillitis | 1 | |
| Agitation | 3 | 1 possibly related to Men C vaccine |
| Convulsions | 3 | |
| Apnoea | 3 | |
| Suspected sepsis | 2 | |
| Maculopapular rash | 3 | 1 possibly related to Men C vaccine |
| Purpuric rash | 3 | |
| Urinary tract infection | 5 | |
| Asthma and wheezing | 2 | |
| Hypotonia | 1 | possibly related to Men C vaccine |
| Chicken pox | 1 | |
| Screaming syndrome | 1 | possibly related to Men C vaccine |
| Peripheral oedema | 1 | |
| Lipoma | 1 | |
| Non-accidental injury | 1 | |
| Unable to hear (parental report) | 1 | normal hearing on testing |
| Total | 161 | |
EUA, examination under anaesthesia.